Finishing machine with a weighing device for the asphalt

ABSTRACT

A finishing machine for the laying of the asphalt surface having a conveyer, and a hopper for the storage and the distribution of material. The conveyer, that moves material from the hopper to the auger, has a couple of chains connected with one another by transversal splines that are suitable for the transport of the material. The material crawls on a plurality of fixed plates secured to the frame of the machine, and the chains run on the plates. The last plate, which supports the passing material, is floating in comparison with the fixed plate which precedes it. The last plate is on a weighing device, and the device is connected with a control power unit. The control power unit detects a signal relevant to the reading of the weight of the material. The signals are detected at time intervals, depending on the angular speed of the hopper, and allows weighings to take place after all the weighed material has been unloaded from the weighing plate.

BACKGROUND OF THE INVENTION

The present patent regards a finishing machine supplied with a weighingdevice for the asphalt distributed by it.

DESCRIPTION OF THE RELATED ART

As it is known, finishing machines or vibratory finishing machines aremachines that lay a layer of new asphalt surface after the carriagewayhas been prepared and after the old asphalt has been removed byscarifier machines.

Finishing or vibratory finishing machines as known in the art generallyhave a hopper for the storage and the distribution of the asphaltconglomerate. Such machines also have one or two conveyers, which fromthe bottom of the hopper, transport the asphalt on the back of themachine. The finishing machine also has one or two augers thatdistribute the asphalt that is received from the conveyer. A shearingand compacting device with vibratory elements for the compressing of thelaid asphalt surface is also part of the finishing machine.

The thickness of the asphalt replaced on the carriageway, and thereforethe amount of the asphalt itself, is a function of the speed of themachine and of the capacity of the conveyors to distribute the asphaltto the augers. Since the excellence of the asphalting depends, besideson the quality of the conglomerate which is used, also on the thicknessof the laid asphalt, it is very important to know the thickness which isactually deposited by the finishing machine.

The present methods currently known in the art, determine only thethickness of the asphalt by the coring, which is made by sampling ofsome points at random. With this system, it is possible to obtain onlypartial information with regard to the executed work. The measure of thethickness of the asphalt is a measure of the destructive kind whichmeans that the coring causes some holes in the road surface. After thecoring, the holes should be covered again. Besides the need of giving orreceiving a certification of the asphalting work which as been executed,the cost of the asphalting works is also a consideration.

BRIEF SUMMARY OF THE INVENTION

The purpose of the present invention is that of overcoming the limitsbefore mentioned.

One of the purposes of the finishing machine of the invention is forarranging a weighing device in order to determine the weight of thematerial distributed by the machine during the work.

Another purpose is for determining the weight of the materialdistributed in a certain area and/or along a certain stretch of road.

Another purpose is for certifying the amount of asphalt distributed fromthe machine itself along a certain route.

Yet another purpose is fort he machine to give accurate and reliableinformation, and that such information is independent from the workingconditions of the machine itself.

All the stated purposes and other ones as identified later, are achievedby a finishing machine for the laying of asphalt surfaces having: ahopper for the storage and the distribution of the material; at least aconveyer of the material of the hopper; at least one auger for thedistribution of the material; and at least a shearing device for thecompressing of the asphalt.

The conveyer has a couple of chains moved by pulleys and connected withone another by transversal splines suitable for the transport of thematerial taken from the bottom of the hopper. The material is leaned ona plurality of fixed plates anchored to the frame of the machine. Thecouple of chains run on the plates of the machine. The last plate, whichsupports the passing materials before the transfer on to thedistribution auger, is made to swing in comparison with the fixed platewhich precedes it, and the last plate leans on a weighing device. Thedevice is connected with a control power unit which detects the readingof the weight, at time intervals which are a function of the angularspeed of the pulley of the conveyer.

The control power unit allows two following weighings to take placeafter all the weighed material has been unloaded from the weighingplate.

Advantageously, according to the invention, the last one of the plates,which supports the passing material from the hopper to the distributionaugers, is made to swing by a hinge. The hinge is arranged on an edge ofthe plate and it is supported by a weighing device, such as the loadingcells.

The weighing is executed at time intervals which are a function of thespeed of the pulley and of the angle which it runs. Each weighing cantake place every time that the pulley has carried away a length of achain similar to the length of the weighing plate. Accordingly, thecertainty of weighing a new material is achieved.

The control power unit records the weight as a function of the speed ofthe conveyer of the material. The control power unit also receivesinformation relevant to the advancing speed of the machine. As such, itis possible to elaborate the information relevant to the laying of theasphalt according to a certain route of the machine. Also, the machineis supplied with sensors which give the information of the width of thefront of laying of the asphalt. It is clear that the informationrelevant to the weight of the asphalt in following areas and thereforethe information relevant to the thickness of laid asphalt can beobtained.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Further characteristics and peculiarities of the invention will bepointed out during the description of a preferred embodiment of theinvention given as an example but not as a restriction and representedin the enclosed drawings wherein:

FIG. 1 is a side view the finishing machine;

FIG. 1a is a front view of the finishing machine of FIG. 1;

FIG. 2 is a schematic of the conveyer which connects the front hopper tothe distribution augers;

FIG. 3 is an enlarged side view of the weighing plate; and

FIG. 4 is an enlarged perspective view of the covering gasket in betweenthe weighing plate and the plate which precedes it.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the mentioned drawings, it can be observed that thefinishing machine represented in FIG. 1 and indicated as a whole with 1,has a hopper 2 for the storage of the asphalt arranged in front of thecab 3 of the machine. In the rear, as shown in a schematicrepresentation, the distribution auger 4 of the asphalt and the shearingdevice 5, can be observed.

On the bottom of the hopper 2, is a conveyer 6. This conveyer 6transports the conglomerate asphalt 7 from the hopper 2 to thedistribution augers 4. As FIGS. 2 and 3 show, the conveyer 6 is extendedin between two pulleys 61 and 62, on which two guide chains 63 aredistributed. Only one of these chains 63 can be observed in FIG. 2. Inbetween the chains 63, a plurality of transversal splines 64 is presentand they are useful for carrying away the conglomerate of asphalt 7 fromthe hopper 2 to the distribution auger 4. The transversal splines 7crawl on a plurality of plates 8.

The plates 8 are fixed to the frame of the machine and provide the baseon which the passing material leans when moving from the hopper to thedistribution augers 4. As FIGS. 2 and 3 show, the last supporting orweighing plate 81, is not anchored to the frame of the machine but itrests on a loading cell 9. The last fixed plate 8 is hinged on the edgeby the hinge 82. It is clear that when the material passes on theweighing plate 81, the weight of the material will cause the weighingplate 81 to incline towards the bottom, being hinged in 82 and loadingthe loading cell 9. From the loading cell 9 exits a signal 91 which isreceived from the control power unit 10.

A further signal 92 is received by the turns sensor 621 which controlsthe rotation angle of the pulley 62 and its speed. When the rotationangle of the pulley is such that the linear route of the conveyer is thesame as the length of the plate 81, it is clear that all the material ofthe first weighing does not influence the plate after it has beenunloaded and another weighing can be executed, a new material nowpressing on the plate 81.

It is clear that the greater the speed of the pulley 62, the greater isthe quantity of material which passes on the plate 81. Such material isdistributed from the augers 4 and forms the asphalt surface under theshearing device 5.

Also, the information from the sensor 31 which controls the advancingspeed of the wheel 32 of the finishing machine 1, is sent to the powerunit 10. A program is used with the power unit 10 that gives the weightof the asphalt laid along a stretch of road, and relates the measuredweight during a certain time to the road covered by the finishingmachine.

Sensors 51 and 52 can be put near the shearing device wherein the widthof the asphalt surface laid can be controlled by the shearing device.Such sensors 51 and 52 send signal 511 to the power unit 10 making iteasy to obtain the information relevant to the weight of the asphalt fora surface unity of a certain stretch of road.

Similarly, the compressing of the material and the indication of thethickness of the material for every stretch of road can be given by thecontrol power unit 10. All the information which, opportunely organizedcan give a certification of the thickness or the quantity of weight ofthe material laid by the machine along all the route, provided thelength variations of the covered surface are sent to the power unit 10.

Since the machine 1 can work in conditions both on plane and inclinedsurfaces, for example on slopes or descents, it is clear that in suchcase the registered weight by the loading cell 9 is not accurate. Inthis case, the machine of the invention includes an inclination sensoranchored to the frame of the machine and illustrated in FIG. 1.

The inclination sensor 95 emits a signal 951 to the control power unit10 which corrects the weighing of the loading cell with regard thecorrection factor resulting from the inclination of the machine andtherefore to the gravitational component itself.

At last, it can be observed that because the asphalt conglomerate whichpasses on the conveyer is heated, it is easy for the asphalt topenetrate in between a support plate and the other one under theconveyer. Because of this, it is important that the weighing plate 81 isprotected from possible infiltrations of material.

The protection of the weighing plate 81 is accomplished by theapplication of a gasket 83 which has a T shape and which has two wings84 and 85. Each wing 84 and 85 is beveled in order to guarantee theperfect adherence to the plane of each plate 8 and 81. The beveled shapeprevents the passing of material that could penetrate under the gasketitself. The central part 86 of the gasket is inserted between twovertical walls of the plates 8 and 81 in order to protect the hinge 82.The hinge 82 should remain free in order to guarantee that the weighingplate 81 can freely incline as the weight passes over it.

According to what has been described, an advantage of the invention isthat it allows the weight of the distributed material to be determinedduring a specified time and in the space of the finishing machine. Ithas also been illustrated that the distribution of the asphalt surfacefor each square metre of the route covered by the finishing machine canbe determined.

What is claimed is:
 1. A finishing machine for carrying asphalt materialand for laying asphalt surfaces on the ground therefrom comprising: aframe; a hopper for storage and distribution of the material secured tothe frame; a conveyer secured to the frame for conveying the materialfrom the hopper; a distribution auger located at an output end of theconveyer for receiving the material from the conveyor output anddepositing the material on the ground; a shearing device locatedadjacent the auger for compressing the deposited material against theground, said conveyer comprising a pair of endless chains; pulleyscarrying the chains; transversal splines connecting the chains fortransporting the material from the hopper; a plurality of fixed platesanchored to the frame between the chains for supporting the materialthereon; a weighing device secured to at least one of said plurality ofplates for providing a weight signal indicative of the weight of thematerial thereon; a controller being responsive to the weight signal forproducing an indication of the amount of material deposited on theground at time intervals which are a function of the angular speed ofthe pulleys, such that at least two successive weighings take placeafter all the weighed material is unloaded from the weighing device; anda width detector for sensing the width of the asphalt layer distributedby the shearing device and providing a width signal, said controllerbeing responsive to the width signal, such that the resultinginformation is the weight of the asphalt distributed in an area of apredetermined stretch of road.
 2. A finishing machine according to theclaim 1, further comprising a speed sensor for sensing the translationspeed of the finishing machine, and said controller being responsive toa speed signal, such that the resulting information is the weight of theasphalt distributed by the machine along a stretch of covered road.
 3. Afinishing machine according to claim 1, further comprising aninclination detector for sensing the inclination of said machine incomparison with the vertical, and producing an inclination signal, saidcontroller being responsive to the inclination signal for correcting theweight detected when the finishing machine works on non-planar roadroutes.
 4. A finishing machine according to the claim 1, wherein theweighing device comprises a load cell.
 5. A finishing machine accordingto the claim 1, including a gasket located between a trailing edge of ahinged plate and a leading edge of an adjacent plate, said gasketsubstantially being T shaped with two wings opposed to one another and acentrally located depending part, said wings being beveled and disposed,one each, on the surface of each of said hinged plate and said adjacentplate, and the central depending part thereof inserted between the twoplates.